Lubricating oil composition



Patented Mar. 14, 1939 UNITED STATES LUBBICA'I'ING on. comrosrnonRaphael Boson, Craniord;N. 3., assignor to tandan! Oil DevelopmentCompany, a corporation of Delaware No Drawing. Application octobcr 4,1934, Serial No. 748,844

It has been known for some time that hydrocarbon and other lubricatingoils deteriorate by oxidation, and especially the more highly relinedoils, particularly hydrocarbon oils which consist essentially ofparafiin hydrocarbons. Such deterioration by oxidation maybe con trolledby the addition oi substances known as oxidation inhibitors, of whichthe best known are.

phenols or naphtholssnd naphthyl'amines, although a great many othersare known.

The present application deals with a new class of oxidation inhibitorsparticularly useful for lubricating oils, including hydrocarbonlubricating oils, and these may be generally described as thosecontaining an iso-cyanic radical which is represented by the formulaXCN, where X represents either an oxygen or a sulphur atom. It ispreferred to use esters of iso-cyanic and isothio-cyanic acids. Thealkyl esters may be used, for example those of the lower alcohols, suchas methyl, ethyl, the propyl and butyl alkyl esters, either straightchain or with branch chain structures, such as isopropyl and secondarybutyl isocyanates. Higher alkyl esters may also be used as well as theesters oi. unsaturated alcohols such as allyl iso-cyanate, vinyliso-thio-cyanate and the corresponding propargyl esters,'and the like.134- and polyhydric alkyl esters of these acids may beused and these maybe fully esterified or,

if desired, only one of the two ormore hydroxy groups need beesterifled.

Besides the alkyl iso-cyanates and iso-thiocyanates aryl esters may alsobe employed, such as the phenyl or naphthyl esters of the acidsspecified above, and of particular interest are the alkylated phenolicand naphtholic esters of such acids, which are more soluble in the oilsthan the corresponding unalkylated esters. 1

The esters may be added in relatively small amounts; for example aslittle as .1% is efl'ective, although more is generally used, say from2% to .5%. On the other hand, as muchas 1% is generally unnecessary.These compounds may be added to the oil as such and dissolvul in somesolvent such as benzol or toluol and. dispersed through the heavier oil.I i

The oils in which the present class of inhibitors may be used aregenerally described as well refined lubricating oils. Petroleumlubricating oils may be obtained from any desirable crude source, suchas paraflin, asphalt or mixed base crudes, and may be refined byordinary methods, such as distillation, acid'and clay treatment, or byspecial methods including hydrogenation, de-- structive hydrogenation,solvent extraction and heavy acid treatment with concentrated or fumingacid or olenm such as is used for the preparation or white oils formedicinal or technical purposes.

Whiie cyanides and cyanates and cyanuric acid compounds have been usedfor various purposes in conjunction with hydrocarbon and other oils, itwill be understood that the iso-cyanates and the iso-thio-cyana'tes area quite different class of compounds and in general are much moreefiective for the. present purposes than the cyanocompounds knownhitherto. As examples of the action of the present class of compounds,the fol lowing may be considered:'

Example 1 to a circulatory path and at fifteen-minute intervals thevolume of oxygen absorbect was measured bydifierence. The result ofthese tests is included inthe following table:

Oxygen absorption cc. of oxygen 10 Oilsample cc. sample 15- minuteintervals at 200 C.

Lubricating oii (blank) 190-80-83 Same containing .2% allyliso-thiocyanate-.." 18-100 Same containing 2% ethyl-thio-cyanate 171-94The above quoted results indlcatethat the thiocyanate produced little,if any, reduction in oxidation rate while the iso-thio-cyanate greatlyreduced the rate.

Example 2 Samples of the oils used above were then subiected to a conedeposit test, which measures the tendency of oils to deposit sludge atelevated I itiehiperialtfiresp these-I testjs the 201 1 was passed I I I{of the 611 has passed threugh :thezco'ne theznaph the insoluble;residue: adhering w the cone? and I I v cb'ziteine d in the 011ilsgcdllatted an recorded;

- g :In these tests the biank sample showed a value, i ,Oif ES; 98 0; ofIthe oil against; for; 1

' included in the fol lbwing table: 5

DISCLAIMER QLUBRICATINGIOIL Gomrosrrlou Patent -1 I I I I IdatedIVIai'ch14f-1939;

{0 Gazette'July 2, 1 9.40.]

, I atfajfixedf rate thmugha grooveeut; in; the inner 1 I j I :eurfa'eeat a steel cone org-standardized dimensions; 5 Z I l i :Which, isfhatdtq 250: C 1 After; 9; Med ivmume 3 l I I I i namerf sa le :or a mineral:lubricating on I 8.5 A; E5 50 grade was subjected .130 the; oxidaticgmtest along: with two Samples containing .-2 bi i I pheny'l 1so-cyanate'andpheny1 1so+thic+cyanatm l f respectively. I "The oxidationrat s Obtained: are I l i .1 *1; Composition according to claim; 2 o!xygen/IO: I

sampla!15- I I the added s'ubstaheeis en alklvl e'ster oriswmoe;cyanicaeidi y The lubnc-ating oils described above, may con-=;-. q ,5tain'additional ingredlentsysuchaszdyes:for'cast; I

or l thic eners, y ur i h b tors oap 1 11s i I I persinig agents; andthe 111m; 1 y

oune: amen 01- m oxidetiong inhibitm snnr m. g;

g'iany particulaeoi li nor to any; perticular mhibitory I I i but; onlyto the following} claims in which it isj I j l I i desired} to, iclaim,9,1! novelty f1iheIBIit in th 6 111+; l I I I vention i I j .j

, g I -1.iCompo'sition of matter eampnsmg a jviscQusQ Iminerallubricating oil and e-smjall: amount of an, I g

I i s'q-cyanic cbmpound selected from the class can I I sistlng of acidsand esters; soluble therein; 7 I I 2, Cumpositiongo f matter comprising;a, vl'seouis' Q 3 i imirierallubricatinepifandafimall amount; Qf Iesterselected from the; class iOf alkyl end aryl; estershof'iso cyanicaclds.{.ff i I 3.?Composition aceordlnggto claim: 2 in :whieh I the ester isan ester of iso thio-cyanic :acid. I

in whien I 5. Cemposition according to; claim 2 in which i i a i I I a,Compasition incoming: to claim; 2 1m which;

lithe adgledeubstance isanalwl ester pf isqi 'WM a d-Jf 'entersthi s disclaimerto 1a" iqfsai LettersBatent jfjjmf

